Statistics of Income (SOI) County-to-County Migration Data is a dataset exposed by Data.gov. The data describes year-to-year address changes between counties and states as reported on individual tax returns. Migration data is exposed through two distinct methods. The Inflow method returns data on the number of new residents in a county or state and where those residents migrated from. The Outflow method returns data on the number of residents leaving a county or state and where they went. Both methods are able to return the total gross income of the migrants.